Phototaxic behaviour of Moina

19 July 2021

Positive Phototaxic behaviour of Moina

Research question - to Check the Phototaxis Behaviour of Moina

Hypothesis - Moina are Positively Phototactic (attracted towards light )

Experiment Design
Experimental Design

we use the glass Fishtank Of length 29.5 cm and width 16.5 cm
Beneath which we kept a black paper divided into 15 equal sections of the same length (29.5 cm) and width (16.5 cm)
The length of one section is 5.9 cm and the width 5.5 cm

We added an M1 Moina culture of 125 ml The chlorinated water and approximately 150 Moina

Total volume after transferring M1 culture in the tank - 2 litres

Number of Moina in each section at different intervals of time
Moina count at different Intervals

The first reading (in black) is taken without any light source to calculate the
Approximate total number of Moina in tank

So assuming the number is between 150 and 170 is a safe bet

As time passes the number of Moina increased in the box closest to the light source!!

Clip of the experiment


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calculating the intensity of light
Calculations Intensity of Light

App used to measure the intensity of light -
Physics Toolbox Sensor Suite

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24 July 2021
we tried keeping the Light source at both ends at different intervals of time

Light source kept at one end - 10:50 pm
Light source kept at the opposite end - 11:43 pm

Light at the opposite end (not at the same time)

Clip of the Experiment

We also tried observing the behaviour of Moina in higher intensity
Level 4 intensity

behaviour of Moina in higher intensity

what happens when a light source of low intensity is kept at the opposite end (2 light sources simultaneously)

2 light source simultaneously added

What happens at low intensity of light
Level - After adding tissue to the light source

Adding tissue to the light source

Calculating the intensity of light
WhatsApp Image 2021-08-01 at 3.20.54 AM


Please can you explain your results after placing a second flash at opposite end

By placing the second light we wanted to see whether we could get more than the average 120-125 number of Moinas(plus 10 to 15 on the opposite side that was in the box opposite which was in the dark) in the two boxes that would be closest to the light but it seemed to make no difference and the total number of moinas combined near the sources were not more than 130-135 average, which could also suggest that a certain number of Moinas in that population were not phototaxic at all, however we would hold this conclusion for more experiment that we will conduct with an updated better design.